We might now think of these diminutive pre-Furby creatures as more adorable than alarming, but the sight of one of them exploding in a microwave – among several other icky stretches in this zesty, family-oriented horror-comedy – was enough to convince the MPAA, after similar concerns over “Indiana Jones and the Temple of Doom” the same summer, to invent the PG-13 rating for future such efforts. Perhaps one to save for Christmas rather than Halloween, but wicked fun on either holiday.